Vacuum casting is a means of casting small metal parts or jewelry that have fine etail or for casting various plastic materials. A porous or vented mold is used and is placed on a table or container where vacuum is applied. The liquid to be cast will be driven into the mold by atmospheric pressure, while the vacuum will also remove trapped air that would otherwise impede the free flow of the liquid casting material. Vacuum casting is applied as an alternative to centrifugal casting of metals which is used in similar situations.